This research project is designed to investigate a proposed role for the "active" form of orosomucoid (alpha 1-acid glycoprotein) as a cofactor in the lipoprotein lipase reaction. It has been established that the "active" component of the orosomucoid fraction isolated from the urine of nephrotic patients is a glycosaminoglycan (GAG). The propsed work involves identification of this GAG by physical, chemical and enzymatic techniques. Techniques will be developed to assay this GAG in plasma of normal subjects, nephrotic patients and patients with diabetic nephropathy. The mechanism of action of GAG or the orosomucoid-GAG complex in the lipoprotein lipase reaction in vivo and in vitro will be investigated.